Buffer for well swabs



D@- 9, 1930. N. H. RICKER BUFFER FOR WELL SWABS Filed Aug. 24, 1929 6 Z/J a/J nu M wv Patented Dec.` 9, 1930 UNITED STATES A NOBHAN H. HIGHER, F HOUSTON, TEXAS, ASSIGNOB TO HUGHES TOOL COMPANY, Ol'

HOUSTON, TEXAS, A CORPORATION OF TEXAS BUFFER FOB WELL SWABS My invention relates to means for stopping a pneumatically operated well swab at the upper end of its stroke, and to prevent damage to the swab and the well structure.

In the operation of pneumatically actuated well swabs to lift liquids from deep wells, it sometimes happens that the plunger is forced upwards 1n the eduction tube without a load of liquid above it, due to a failure of the liquid and air to exhaust quickly behind the plunger, so that in dropping, the plunger is cau ht in the air exhaust, and in such case the p unger is blown back with high speed like a rojectile, tending to strike the upper end o the tube with great force and damage both the swab and the well tube.

It is an object of this invention to provide a means to stop the plunger at the-upper limit of its travelwithout danger to the plunger or to the pipe.

I desire to equip the eduction tube with shock-absorbing means for the swab plunger, whereby damage to the equipment 1s avoided. v

In the drawin is shown a central longitudinal section t rough a pneumatically operated pumping device employingmy invention. Fi 1 illustrates the structure at the upper en of the well and Fig. 2 shows the lower end of the apparatus.

My swab apparatus includes an outer casing 1 for the well. The upper end of the well casing has a special casing-head 2 thereon, with a lateral outlet 3 donnected with a pipe 4 to carry the liquid to storage. The upper end of the casing head 3 has a tubular nut or bushing 5 screwed therein, provided with radial handles 6 thereon to furnish means to rotatethe same.

The u per end of the bushing 5 is threaded internal y to receive an elongated cap or bull plu 7 closing the upper end of the casing hea and acting to house the upper end l of the eduction tube.

The eduction tube is double walled for the greater part of its length. The outer wall or pipe 8 extends downwardl into the well and toward its lower end may swaged inward#` l at 9 and connected to a pipe 10 of smaller diameter. The upper end of the pipe 8 is-y connected with a head 11 shaped to fill the inner circumference of the casing head below i the outlet 3 and to rest upon a shoulder 12 in said casing head. Its upper end is reduced in diameter adjacent the outlet and terminates at its upper'end in a tubular projection 13 slotted at I4 to allow t-he outlet of liquid therefrom. Above the outlet, the projection connects with a nip le 15 which is housed in the bull plug 7, an has at its upper end, a fitting 16 o larger internal diamete than the nipple. It is closed at its u per en by a nut or plug 18. Within the ttin 17 is a thick pad of rubber or other resient material 17 which fills the fitting and rests at its lower'end upon the upper end of the nipple 16. This ru ber pad 1s referably cored out axially to provide space or lateral expansion of the rubber of the pad when the plunger engages therewith.

The inner tube 2O for the eduction of the ,liquid is spaced slightly from the outertube necting with an inlet passage 27 for the pres# sure fluid. The upper end of the inner eduction tube is seated in the lower end of the head 11 and makes a tight fit therewith. The space between the tubes 8 and 20 forms a passage for the pressure fluid entering through a lateral passage 29 in the casing head, which receives the fluid from an inlet pipe 30 which is connected with a source of supply of air or gas under pressure, not shown. f

The swab plunger 25 may be of any preferred form. I have shown a plunger having an outer cylindrical face shaped to fit within the inner tube 420. Its lower end is reduced in diameter and has a guide passage thereinv for the valve stem upon the valve 31.r `Said valve is normally open by` avit but seats upwardly by 'the force o air low the same. In the drawing, the valve is shown closed. y

' In the operation of my device, the liquid enters the eduction tube through the passage 22 and as the valve 31 is then open by gravity, the li uid will lill the eduction tube to the desire height. The air pressure will then be turned on and will enter the chamber 26 below the plunger and close valve 31 and raise the swab and its load to the surface. The liquid load will discharge through the outlet slots 14 to the interior of the casing head and will pass out through the pipe 4. Some air and liquid will pass the openings 14 into the nipple 15. I/Vhen the swab plunger reaches the upper end and its load of liquid has been discharged, it will move into the nipple 15. The liquid in the nipple will normally absorb the force ofthe plunger and will move the valve to open position, so that the plunger may dro to its seat at the lower end of the tube. I however, the plunger comes up with no liquid above it, it will be shot past the outlet opening and willl engage the rubber buffer and will be stopped without danger taffthe swab or the rest o the apparatus. The valve will be closed when the swab contacts with the buier, but as the swab drops back in the rising air discharge, it will surge back and forth near the outlet until the valve drops open and then the swab `will fall'.

What I claim as new is:

1. In a pneumatic swab structure, an eduction tube, a plunger therein, a downwardly opening valve in said plunger, a nipple at the upper end of said eduction tube, t ere Vbeing lateral liquid discharge openings adjacent the lower end of said nipple, means to allow the introduction of pressure iluid below said plun er, and means in said nipple to be engage by said plunger and absorb the force of its upward movement.

2. In a neumatic swab structure, an eduction tube aving lateral discharge openings adjacent to its upper end, an elongated nipple above said openings, shock absorbing means at the upper end of said nipple, a plunger in said tube and means to introduce pressure fluid below said plunger.

3. In a pneumatic swab structure, an educ- -tion tube having lateral discharge openings adjacent to its upper end, an elongated nipple above said openings, shock absorbing means,

including a resilient cushion of flexible material at the upper end of said nipple, a plunger in said tube and means t'o introduce pressure fluid below said plunger.

4. In a pneumatic swab structure, an eduction tube having lateral discharge o nings adjacent to its upper end, an elongate nipple above said openings, a tubular-block of ilexible shock-absorbing material "fixed at the upper end of said nipple, a 'plunger in' said tube and means to introduce pressure Huid below said plunger.

5. In a pneumatic swab structure including an eduction tube having lateral outlet openings therein at its upper end, a plunger in said tu e and means to introduce pressure below said plunger, the combination of a nip le connected with the upper end of said tube,

.means to close the upper end of said nipple and a resilient cushion for said plunger with'- in said nipple.

6. In a pneumatic swab structure including an eduction tube having lateral outlet openings therein at its upper end, a plunger in said tube and means to introduce pressure below said plunger, the combination of means to close the upper end of said tube above said openings, and means to receive said plunger and absorb the force of its upward movement.

. 7 In a pneumatic swab structure including an eduction tube having lateral outlet openings therein at its upper end, a plunger in said tu e and means to introduce pressure below said plunger, the combination of means to close the upper end of said tube and a rubber sleeve to receive said plunger and limit its upward movement.

In testimony whereof, I hereunto aix my signature this 16th day of Au st A. D. 1929.

NORMAN RICKER. 

